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TECHNICAL BULLETIN
LTB00443NAS1
30 SEP 2013
© Jaguar Land Rover North America, LLC
NOTE: The information in Technical Bulletins is intended for use by trained, professional Technicians with the knowledge, tools,
and equipment required to do the job properly and safely. It informs these Technicians of conditions that may occur on some
vehicles, or provides information that could assist in proper vehicle service. The procedures should not be performed by 'do-ityourselfers'. If you are not a Retailer, do not assume that a condition described affects your vehicle. Contact an authorized Land
Rover service facility to determine whether this bulletin applies to a specific vehicle.

SECTION: 413-06

Additional Force Required To Operate The Horn
AFFECTED VEHICLE RANGE:
LR4 (LA)
Model Year:
VIN:

2010 Onwards
AA510742 Onwards

Range Rover Sport (LS)
Model Year:
2010-2013
VIN:
AA212147-DA814822
Range Rover (LM)
Model Year:
2010-2012
VIN:
AA304426-CA393639

MARKETS:
NAS

CONDITION SUMMARY:
Situation: Additional force may be required to operate the horn.
Cause: This may be caused by the contacts in the horn pad.
Action: Should a customer express this concern, follow the Service Instruction outlined below.

PARTS:

NOTE: For horn switch part numbers, please refer to MicroCat.
LR040238

Horn suppression kit

Quantity: 1

TOOLS:
Refer to Workshop Manual for any required special tools.

WARRANTY:
NOTE: Repair procedures are under constant review, and therefore times are subject to change;
those quoted here must be taken as guidance only. Always refer to TOPIx to obtain the latest repair
time.
NOTE: DDW requires the use of causal part numbers. Labor only claims must show the causal part
number with a quantity of zero.
DESCRIPTION

Horn switch harness modification - LR4,

SRO

TIME
(HOURS)

CONDITION
CODE

CAUSAL
PART

86.71.89/45

0.90

42

LR030358

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Range Rover Sport
Horn switch harness modification - Range
Rover

86.71.89/45

0.70

42

LR015173

NOTE: Normal Warranty policies and procedures apply.

SERVICE INSTRUCTION:
Steps 1-15: LR4, Range Rover Sport only

1.

NOTE: Driver air bag module shown
removed for clarity.
Rotate the steering wheel to allow access to the
four (4) Torx bolts on the horn switches.

2.

CAUTION: Do NOT connect the battery negative (-) cable until step 15.
Remove the driver air bag module (see TOPIx Workshop Manual, Section 501-20B).

3. Remove the four (4) Torx bolts.

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4.

CAUTION: Note the fitted position of the
component prior to removal.
Remove the right-hand (RH) horn switch assembly.
Disconnect the electrical connector.

5.

CAUTION: Note the fitted position of the
component prior to removal.
Remove the left-hand (LH) horn switch assembly.
Disconnect the two (2) electrical connectors.

6.

NOTE: The new LH horn switch may be
equipped with a link lead; this can be
removed and discarded.
Install the RH and LH horn switches:
Reverse steps 3-5.
Tighten the four (4) Torx bolts to 6 Nm.

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7.

CAUTION: Do NOT connect the battery negative (-) cable during this step.
Install the driver air bag module (see TOPIx Workshop Manual, Section 501-20B).

8.

CAUTION: Make sure that the battery negative (-) cable is disconnected.
Remove the Central Junction Box (CJB) (see TOPIx Workshop Manual, Section 418-00).

9. Identify the wire to be cut (see TOPIx Electrical
Reference Library).
Connector - C0584; Pin - 28; Color -

Brown/Green (NG)
Release the insulating tape to allow access to

the wire.

10. Using a suitable tool, cut the wire approximately
50mm from the connector.

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11.
CAUTION: Make sure that the surrounding components and trim are suitably protected when
using the heat gun; failure to follow this instruction may result in damage to the vehicle.

CAUTION: Make sure that the exposed ends of the cut wire are fully insulated with the heat
shrink.
Using a suitable heat gun, install a piece of heat shrink to the each end of the exposed wire.
12. Using a suitable tape, secure the ends of the
wires to the existing harness.

13.

CAUTION: Do NOT connect the battery negative (-) cable during this step.

Install the CJB (see TOPIx Workshop Manual, Section 418-00).
14. Replace the horn relay:
Remove the engine fuse box cover.

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Remove and discard relay R5.
Install the new relay.
Install the engine fuse box cover.

15. Connect the battery negative (-) cable.

Steps 16-32: Range Rover only.

16. Open the lower glove compartment.

17.

CAUTION: Do NOT connect the battery negative (-) cable during this step.

Replace both horn switches (see TOPIx Workshop Manual, Section 413-06).
18. Remove the cowl side trim panel (see TOPIx Workshop Manual, Section 501-05).
19. Remove the floor console trim panel (see TOPIx Workshop Manual, Section 501-12).
20. Remove the passenger side closing trim panel.
Remove the three (3) screws.
Disconnect the footwell lamp electrical connector.

21. Open the lower glove compartment to the service
position.

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22. Release the three (3) connectors.

23. Reposition the Central Junction Box (CJB).
Remove the two (2) bolts.

24. Disconnect the electrical connectors.

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25. Identify the wire to be cut (see TOPIx Electrical
Reference Library).
Connector - C0584; Pin - 28; Color -

Brown/Red (NR)
Release the insulating tape to allow access to

the wire.
Remove and discard the tie strap from the

connector.

26. Using a suitable tool, cut the wire approximately
50mm from the connector.

27.

CAUTION: Make sure that the surrounding components and trim are suitably protected when

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using the heat gun; failure to follow this instruction may result in damage to the vehicle.

CAUTION: Make sure that the exposed ends of the cut wire are fully insulated with the heat
shrink.
Using a suitable heat gun, install a piece of heat shrink to the each end of the exposed wire.
28. Using a suitable tape, secure the ends of the
wires to the existing harness.

29. Using a suitable tie strap, secure the harness to
the connector.

30.

CAUTION: Do NOT connect the battery negative (-) cable during this step.

Install the CJB:
Reverse steps 18-24.
Tighten to CJB bolts to 10 Nm.

31. Replace the horn relay:

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Remove the engine fuse box cover.
Remove and discard relay R8.
Install the new relay.
Install the engine fuse box cover.

32. Connect the battery negative (-) cable.

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